Originally Posted by skupples
Sigh... @IT Diva
I'm becoming quite conflicted over this triple DDC action. Now have two people saying it fries pumps. Derick proclaims EK told him to tell us triple DDC = dead pumps, B-Neg said the same thing. Yet neither of them can actually give any evidence towards these opinions.
Might do a dual loop, wonder how much of a PITA it would be to run dual loop from one reservoir.
Everyone reacts to what others say differently . . . .
Most of us have different levels of education, experience, and expertise to evaluate what we hear from others, and how we evaluate data.
I'm one of the "Show me your evidence, and if I find it sufficiently compelling, I'll accept your finding" types.
I haven't seen anyone post any testable evidence or mechanism by which 3 pumps instead of 2 results in failure of 1 of them.
What I've seen is anecdotal at best, and with little additional information, so that we have nothing else to look at to weigh.
Additionally, it seems they were referring to fixed speed DDC versions, not including the PWM 35X, which from the get-go, is designed to be a variable speed device.
I'm not sure if it's been posted as to whether the failures were on voltage controlled pumps, or just fixed 12V setups.
When there is considerable
anecdotal suggestion, it may well suggest that it's time for some true investigation, but absent any results of that kind of investigation, absent any details of the systems they were in or speeds they were running at, and absent any methodological mechanism hypothesized for why one of the pumps fails with triples but not doubles, . . . . .
I have to discount those accounts considerably, as they do not posit enough relevant admonition to persuade me to not run the triple 35X setup I currently have on the tech bench.
If at some point, I experience a failure, I'll surely investigate . . . but so far, it's had plenty of run time, and the housings always stay nicely cool.
If I had enough information, I might hypothesize, that pushing 2 pumps into a third essentially allows that third pump to see such a low restriction, that it results in the anecdotally described "DDC low restriction loop failure".
But with the absence of valid information available, that would barely even rank as conjecture, much less hypothesis.
DarleneEdited by IT Diva - 3/23/14 at 10:06am